minio/cmd/untar.go
Harshavardhana 069432566f update license change for MinIO
Signed-off-by: Harshavardhana <harsha@minio.io>
2021-04-23 11:58:53 -07:00

158 lines
3.3 KiB
Go

// Copyright (c) 2015-2021 MinIO, Inc.
//
// This file is part of MinIO Object Storage stack
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package cmd
import (
"archive/tar"
"bufio"
"bytes"
"compress/bzip2"
"fmt"
"io"
"os"
"path"
"github.com/klauspost/compress/s2"
"github.com/klauspost/compress/zstd"
gzip "github.com/klauspost/pgzip"
"github.com/pierrec/lz4"
)
func detect(r *bufio.Reader) format {
z, err := r.Peek(4)
if err != nil {
return formatUnknown
}
for _, f := range magicHeaders {
if bytes.Equal(f.header, z[:len(f.header)]) {
return f.f
}
}
return formatUnknown
}
//go:generate stringer -type=format -trimprefix=format $GOFILE
type format int
const (
formatUnknown format = iota
formatGzip
formatZstd
formatLZ4
formatS2
formatBZ2
)
var magicHeaders = []struct {
header []byte
f format
}{
{
header: []byte{0x1f, 0x8b, 8},
f: formatGzip,
},
{
// Zstd default header.
header: []byte{0x28, 0xb5, 0x2f, 0xfd},
f: formatZstd,
},
{
// Zstd skippable frame header.
header: []byte{0x2a, 0x4d, 0x18},
f: formatZstd,
},
{
// LZ4
header: []byte{0x4, 0x22, 0x4d, 0x18},
f: formatLZ4,
},
{
// Snappy/S2 stream
header: []byte{0xff, 0x06, 0x00, 0x00},
f: formatS2,
},
{
header: []byte{0x42, 0x5a, 'h'},
f: formatBZ2,
},
}
func untar(r io.Reader, putObject func(reader io.Reader, info os.FileInfo, name string)) error {
bf := bufio.NewReader(r)
switch f := detect(bf); f {
case formatGzip:
gz, err := gzip.NewReader(bf)
if err != nil {
return err
}
defer gz.Close()
r = gz
case formatS2:
r = s2.NewReader(bf)
case formatZstd:
dec, err := zstd.NewReader(bf)
if err != nil {
return err
}
defer dec.Close()
r = dec
case formatBZ2:
r = bzip2.NewReader(bf)
case formatLZ4:
r = lz4.NewReader(bf)
case formatUnknown:
r = bf
default:
return fmt.Errorf("Unsupported format %s", f)
}
tarReader := tar.NewReader(r)
for {
header, err := tarReader.Next()
switch {
// if no more files are found return
case err == io.EOF:
return nil
// return any other error
case err != nil:
return err
// if the header is nil, just skip it (not sure how this happens)
case header == nil:
continue
}
name := header.Name
if name == slashSeparator {
continue
}
switch header.Typeflag {
case tar.TypeDir: // = directory
putObject(tarReader, header.FileInfo(), trimLeadingSlash(pathJoin(name, slashSeparator)))
case tar.TypeReg, tar.TypeChar, tar.TypeBlock, tar.TypeFifo, tar.TypeGNUSparse: // = regular
putObject(tarReader, header.FileInfo(), trimLeadingSlash(path.Clean(name)))
default:
// ignore symlink'ed
continue
}
}
}